Monitoring and diagnosing a technical installation using purely mechanically activated signaling means

ABSTRACT

A specific failure occurring during operation of a technical installation is detected by acquiring an acoustic and/or optical signal emitted by a device assigned to at least one component of the technical installation whereby the device is being activated mechanically.

CROSS REFERENCE TO RELATED APPLICATION

This application is the US National Stage of International ApplicationNo. PCT/EP2002/011867, filed Oct. 23, 2002 and claims the benefitthereof. The International Application claims the benefits of EuropeanPatent application No. 02021498.7 EP filed Sep. 26, 2002, both of theapplications are incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The invention relates to a method respectively apparatus for monitoringa technical installation.

BACKGROUND OF THE INVENTION

In industrial plants, especially in power plants, condition monitoringof main systems (e.g. turbines and/or generators) sub-systems (e.g.water-steam-cycle) and components (e.g. pumps, motors, drives, valves,pipes, bearings etc.) of the plants is essential to guarantee reliableoperation. Condition monitoring often includes a quasi non-stopacquisition and storing of data relevant for the operation of the plant.

In order to adjust operation parameters during operation of the plant,schedule maintenance and repair work, and to minimize safety risks,accurate data about the condition of numerous plant assets must begathered and analyzed. The nature of a.m. data needed is manifold andthe impact of said data on actual plant failures is often hard todetermine.

Typical examples of condition monitoring data are vibration data (e.g.of turbines or pumps, often acquired by vibration sensors and analyzedby a specialized evaluation device using spectrum analysis or the like),temperature and/or pressure data (e.g. of boilers, acquired inside theboiler via sensors or calculated indirectly using related data), volumedata (e.g. throughput of a pipeline) and so on.

There are technical means, e.g. sensors, to collect most of the desireddata. However, for a complete and reliable picture of a plant's actualcondition, the amount of data needed is enormous.

This is a problem both in terms of installation costs of sensors, and interms of efforts to analyze the resulting sensor data.

As a consequence, the majority of plant owners cannot afford anall-embracing monitoring of all plant assets.

Therefore, unscheduled drop outs of production are inevitable, oftenresulting in a loss of income and/or high penalties.

Known methods of monitoring the condition of industrial plants mayinclude:

Collecting data and reporting related values, e.g. on-line or off-linestatuses, using sensors attached to the components to be monitored; saidsensors may include vibration sensors for rotating machinery (e.g.generators, turbines) and/or thermography (e.g. temperature) sensors forboilers.

If a component is being monitored on-line, sensors are usually connectedto an evaluation system, which analyzes the data and prompts appropriatemessages related to its condition to the operator, e.g. on a computerscreen or large screen display.

Off-line sensors do not necessarily need to be connected to anevaluation system; data can be collected on demand, e.g. using aportable computer.

Any kind of known methods of sensor based monitoring are usuallyextremely costly.

Not only the actual technical equipment needed, but also the appropriatecommissioning and adjusting of the sensors to the specific needs andenvironmental conditions, take more efforts and financial investmentsthan typical plant owners are able or willing to spend.

And/or

Inspecting machinery by frequent walks across the plant.

Specialist engineers may inspect machinery by a.m. frequent “walkdowns”.

The main “sensor” used for inspection here is human perception.

Due to their knowledge and experience, these engineers are able todetect a broad range of failures.

However, symptoms of many failures simply cannot be sensed withouttechnical aids.

For example, bearings, which start becoming faulty, can only rarely bydetected solely by human perception, or the unwanted change of magneticflux in a pump cannot at all be noticed by man.

Furthermore, long term changes of a machine's characteristic occurringin the course of time are very hard to realize since there no directcomparison available with a regular operation mode.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide an improved andaffordable method respectively apparatus for monitoring a technicalinstallation, especially for carrying out diagnosis.

A method according to the invention comprises acquiring at least oneacoustical and/or optical signal assigned to at least one specificfailure of at least one component of the technical installation, wherebysaid acoustical and/or optical signal is being produced by a deviceassigned to said component and said device is being activatedmechanically in case of occurrence of said failure.

An apparatus according to the invention comprises at least one deviceassigned to at least one component of the technical installation forproducing an acoustical and/or optical signal characteristic for atleast one specific failure of said component, whereby said device isactivated mechanically in case of occurrence of said failure.

Preferred embodiments of the invention are laid down in severaldependant claims.

Any embodiment of the invention may include, but will not be limited to,one or more of the following features.

Sub-systems/machinery components are designed in such a way that theyindicate faults acoustically and/or optically.

Instead of attaching sensors to machinery which display measured data ona screen or on legacy computer systems, machinery or components thereofare designed in such a way that faults can clearly be identified bycharacteristic sounds (acoustical signal) and/or that a machine'scomponents are designed in such a way that they change their outerappearance (optical signal), e.g. with regard to their coating color,when a fault occurs.

Especially the acoustical and/or optical signal is directly activated bythe respective failure; e.g. any type of fault may cause a unique sound(“groan”), i.e. the sound's frequency and/or its volume allowidentifying the kind of fault without ambiguity (“groaning machinery”).

The sounds should be identifiable by personnel without technical aidssuch as vibration monitoring devices or sound analysis systems.

Alternatively or in combination therewith each type of fault may causean optical signal assigned to said failure.

This enables a person carrying out a walk across the plant to detectalso faults which normally would be not be sensible by human perception.

A monitoring method and/or apparatus according to the invention does notrequire costly additional sensors since machinery or components thereofby mechanical design make faults obvious for plant personnel byproducing characteristic sounds and/or optical signals perceivable byhuman senses.

Therefore, walks across the plant are much more effective and give amore comprehensive image of a plant's condition without a need forextensive technical diagnosis equipment; without plant-wide sensorinstallations, plant operators may receive all information for makingoperational and maintenance decisions.

Examples of plant components designed to be used according to theinvention:

Rotating machinery, such as pumps or fans, are designed in such a waythat faults in their bearings lead to characteristic noises.

This can be achieved by designing the casing in such a way that faultybearings result in resonance effects.

Faults in different bearings may result in different resonancefrequencies easily detectable and distinguishable by human ears.

Such resonance effects can be made perceivable for example by attachingplates to the casing which vibrate according to body resonance of thecasing.

Supports of pipelines are often designed to adjust flexibly when thepipeline expands due to a change of its temperature.

Abnormal temperature changes lead to abnormal adjustment of the support.A characteristic squeaking of the support would make such abnormaltemperature changes audible to plant personnel.

Electrical machinery produce well defined electric-magnetic flux.

A flux sensitive coating may change color when the flux differs from theexpected flux. Such discrepancies indicate the type of fault inside themachine, i.e. faulty rotors in electrical engines.

Temperature sensitive coatings may change their color and thus reflectdiscrepancies from normal temperatures of machinery.

An abnormal local temperature in a specific area on a machine's surfacemay thus give hints to the type and location of a fault.

For example, local temperature discrepancies in a rotating machine canindicate a faulty bearing.

Vessels containing a liquid of noticeable color can be attached tocomponents of a technical installation.

A vessel, its location and way of attachment are designed in such a waythat the vessel breaks when the machinery or a particular componentthereof suffer excessive strain, for example due to vibration orexcessive pressure.

The liquid leaking from the vessel and spilling over at least part ofthe machine is an optical indication for the (excessive) strain therespective component is or was exposed to.

The advantages of the invention compared to sensor based conditionmonitoring include cost saving and data reduction.

Machinery designed to indicate faults acoustically and/or optically donot require additional sensors to monitor their status.

Since only faults are reported, e.g. by personnel walking across theplant, and no data are reported on machinery components which worksfaultlessly, the amount of data to be processed in evaluation andanalysis systems is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures show preferred embodiments of the invention.

FIG. 1 shows an apparatus according to the invention.

FIGS. 2 and 3 show a vessel, filled with liquid.

DETAILED DESCRIPTION OF THE INVENTION

A pump 5 is designed to indicate a faulty pump bearing 7 acoustically.

Therefore, a plate 9 is fixed at a casing 11 of the pump 5 in such away, that it can vibrate when activated at its resonance frequency, andcause a characteristic noise by hitting e.g. a metal stub 13 on thecasing 11.

The plate 9 is designed in such a way that it has the same bodyresonance frequency as the vibration frequency caused by the bearing 7getting faulty.

Hence, the faulty bearing 7 causes the plate 9 to vibrate and thusproduce a noise characteristic for the faulty bearing 7.

The plate 9 may also be designed to produce a musical note in a specialtune when being activated at its resonance frequency by the faultybearing 7. Concerning that embodiment, the stub 13 may be omitted as thecharacteristic noise is the vibration of the plate 9 itself.

If there are a number of bearings in a plant, the respective plates maybe designed to produce different musical notes so that the plant'spersonnel can tell by the frequency of the note which bearing is faulty.

FIGS. 2 and 3 show a vessel 15, filled with liquid 17, which is fixed ona steel construction 19 by three fixations 21 (see FIG. 2).

When the steel construction 19 suffers excessive stress, e.g. by puttinga weight 23 on top, the vessel 15 breaks and the liquid 17 inside thevessel 15 spills and thus gives indication for the excessive stress thesteel construction 19 has suffered (see FIG. 3).

Using vessels 15 filled with liquids 17 of different colors, which arebe designed to break at different stress limits, may give the operatingand maintenance personnel of the plant a quick and comprehensiveoverview which component of the plant has suffered excessive stressand/or the strength of the respective stress burden.

The invention in general may be summarized as follows:

A specific failure occurring during operation of a technicalinstallation is detected by acquiring an acoustic and/or optical signal(10, 14) emitted by a device (9, 15) assigned to at least one component(5, 19) of the technical installation whereby the device (9, 15) isbeing activated mechanically.

1. An acousto-mechanical method for monitoring and carrying out adiagnosis of a technical installation, comprising: uniquely assigning anacoustical signal to a specific failure of a respective one of aplurality of rotatable components of the technical installation;mounting a respective vibratory device on each of the plurality ofcomponents, wherein the vibratory device is configured to mechanicallygenerate the uniquely assigned acoustic signal in the event the specificfailure of a respective one of the plurality of components occurs,providing in each vibratory device a respective plate; uniquely adaptingeach plate to resonate at a vibration frequency in correspondence withthe uniquely assigned acoustic signal and; based on a soundcharacteristic produced by a plate that resonates at the uniquelyassigned acoustic signal, uniquely identifying the respective one of theplurality of rotatable components of the technical installationexperiencing the failure.
 2. The method according to claim 1, wherein anumber of devices are provided for a single component or a number ofdevices are provided for a number of components, each device beingassigned to a specific failure.
 3. The method according to claim 1,wherein a number of devices are provided for a single component, eachdevice being assigned to a specific failure.
 4. An acousto-mechanicalapparatus for monitoring and carrying out a diagnosis for a power plant,comprising: a respective vibratory device mounted on each of a pluralityof components of the power plant for mechanically producing a uniquelyassigned acoustical signal when a specific failure occurs in arespective one of the plurality of rotatable components of the powerplant, each vibratory device including a respective plate, each plateuniquely adapted to resonate at a vibration frequency in correspondencewith the uniquely assigned acoustic signal, wherein, based on a soundcharacteristic produced by a plate that resonates at the uniquelyassigned acoustic signal, the device allows a user to uniquely identifythe respective one of the plurality of rotatable components of thetechnical installation experiencing the failure.
 5. The apparatusaccording to claim 4, wherein a number of devices are provided for asingle component or a number of devices are provided for a number ofcomponents, each device being assigned to a specific failure.
 6. Theapparatus according to claim 4, wherein a number of devices are providedfor a single component, each device being assigned to a specificfailure.